Low-Frequency Vibrational States in Ideal Glasses with Random Pinning

TL;DR

This study investigates how localized low-frequency vibrational modes in ideal glasses persist through the glass transition using random pinning, revealing their continued presence and characteristic properties in equilibrium states.

Contribution

It demonstrates that localized vibrational modes survive the ideal glass transition and retain their $ ext{ω}^4$ density of states, advancing understanding of glassy vibrational properties.

Findings

Localized vibrations persist in equilibrium glasses.

Vibrational density follows $g( ext{ω}) \,\propto\, \text{ω}^4$ below boson peak.

Localized modes survive through the glass transition.

Abstract

Glasses exhibit spatially localized vibrations in the low-frequency regime. These localized modes emerge below the boson peak frequency $\omega_\text{BP}$, and their vibrational densities of state follow $g(\omega) \propto \omega^4$ ($\omega$ is frequency). Here, we attempt to address how the localized vibrations behave through the ideal glass transition. To do this, we employ a random pinning method, which enables us to study the thermodynamic glass transition. We find that the localized vibrations survive even in equilibrium glass states. Remarkably, the localized vibrations still maintain the properties of appearance below $\omega_\text{BP}$ and $g(\omega) \propto \omega^4$. Our results provide important insight into the material properties of ideal glasses.